/**
 * Abstract base class for filter implementations.
 */
Ext.define('Ext.ux.grid.filter.Filter', {
			extend : 'Ext.util.Observable',

			/**
			 * @cfg {Boolean} active Indicates the initial status of the filter
			 *      (defaults to false).
			 */
			active : false,
			/**
			 * True if this filter is active. Use setActive() to alter after
			 * configuration.
			 * 
			 * @type Boolean
			 * @property active
			 */
			/**
			 * @cfg {String} dataIndex The {@link Ext.data.Store} dataIndex of
			 *      the field this filter represents. The dataIndex does not
			 *      actually have to exist in the store.
			 */
			dataIndex : null,
			/**
			 * The filter configuration menu that will be installed into the
			 * filter submenu of a column menu.
			 * 
			 * @type Ext.menu.Menu
			 * @property
			 */
			menu : null,
			/**
			 * @cfg {Number} updateBuffer Number of milliseconds to wait after
			 *      user interaction to fire an update. Only supported by
			 *      filters: 'list', 'numeric', and 'string'. Defaults to 500.
			 */
			updateBuffer : 500,

			constructor : function(config) {
				Ext.apply(this, config);

				this.addEvents(
						/**
						 * @event activate Fires when an inactive filter becomes
						 *        active
						 * @param {Ext.ux.grid.filter.Filter}
						 *            this
						 */
						'activate',
						/**
						 * @event deactivate Fires when an active filter becomes
						 *        inactive
						 * @param {Ext.ux.grid.filter.Filter}
						 *            this
						 */
						'deactivate',
						/**
						 * @event serialize Fires after the serialization
						 *        process. Use this to attach additional
						 *        parameters to serialization data before it is
						 *        encoded and sent to the server.
						 * @param {Array/Object}
						 *            data A map or collection of maps
						 *            representing the current filter
						 *            configuration.
						 * @param {Ext.ux.grid.filter.Filter}
						 *            filter The filter being serialized.
						 */
						'serialize',
						/**
						 * @event update Fires when a filter configuration has
						 *        changed
						 * @param {Ext.ux.grid.filter.Filter}
						 *            this The filter object.
						 */
						'update');
				Ext.ux.grid.filter.Filter.superclass.constructor.call(this);

				this.menu = this.createMenu(config);
				this.init(config);
				if (config && config.value) {
					this.setValue(config.value);
					this.setActive(config.active !== false, true);
					delete config.value;
				}
			},

			/**
			 * Destroys this filter by purging any event listeners, and removing
			 * any menus.
			 */
			destroy : function() {
				if (this.menu) {
					this.menu.destroy();
				}
				this.clearListeners();
			},

			/**
			 * Template method to be implemented by all subclasses that is to
			 * initialize the filter and install required menu items. Defaults
			 * to Ext.emptyFn.
			 */
			init : Ext.emptyFn,

			/**
			 * @private
			 * @override Creates the Menu for this filter.
			 * @param {Object}
			 *            config Filter configuration
			 * @return {Ext.menu.Menu}
			 */
			createMenu : function(config) {
				config.plain = true;
				return Ext.create('Ext.menu.Menu', config);
			},

			/**
			 * Template method to be implemented by all subclasses that is to
			 * get and return the value of the filter. Defaults to Ext.emptyFn.
			 * 
			 * @return {Object} The 'serialized' form of this filter
			 * @template
			 */
			getValue : Ext.emptyFn,

			/**
			 * Template method to be implemented by all subclasses that is to
			 * set the value of the filter and fire the 'update' event. Defaults
			 * to Ext.emptyFn.
			 * 
			 * @param {Object}
			 *            data The value to set the filter
			 * @template
			 */
			setValue : Ext.emptyFn,

			/**
			 * Template method to be implemented by all subclasses that is to
			 * return <tt>true</tt> if the filter has enough configuration
			 * information to be activated. Defaults to <tt>return true</tt>.
			 * 
			 * @return {Boolean}
			 */
			isActivatable : function() {
				return true;
			},

			/**
			 * Template method to be implemented by all subclasses that is to
			 * get and return serialized filter data for transmission to the
			 * server. Defaults to Ext.emptyFn.
			 */
			getSerialArgs : Ext.emptyFn,

			/**
			 * Template method to be implemented by all subclasses that is to
			 * validates the provided Ext.data.Record against the filters
			 * configuration. Defaults to <tt>return true</tt>.
			 * 
			 * @param {Ext.data.Record}
			 *            record The record to validate
			 * @return {Boolean} true if the record is valid within the bounds
			 *         of the filter, false otherwise.
			 */
			validateRecord : function() {
				return true;
			},

			/**
			 * Returns the serialized filter data for transmission to the server
			 * and fires the 'serialize' event.
			 * 
			 * @return {Object/Array} An object or collection of objects
			 *         containing key value pairs representing the current
			 *         configuration of the filter.
			 */
			serialize : function() {
				var args = this.getSerialArgs();
				this.fireEvent('serialize', args, this);
				return args;
			},

			/** @private */
			fireUpdate : function() {
				if (this.active) {
					this.fireEvent('update', this);
				}
				this.setActive(this.isActivatable());
			},

			/**
			 * Sets the status of the filter and fires the appropriate events.
			 * 
			 * @param {Boolean}
			 *            active The new filter state.
			 * @param {Boolean}
			 *            suppressEvent True to prevent events from being fired.
			 */
			setActive : function(active, suppressEvent) {
				if (this.active != active) {
					this.active = active;
					if (suppressEvent !== true) {
						this
								.fireEvent(active ? 'activate' : 'deactivate',
										this);
					}
				}
			}
		});
